Bush Bush Bush Wood Wood Wood

1
Black Green Orange Red Yellow

5 2 1 9 3
2
Black Green Orange Red Yellow

4 5 4 4 3
3
Black Green Orange Red Yellow

7 1 1 2 9
4
Black Green Orange Red Yellow

7 1 2 2 8
5
Black Green Orange Red

4 6 9 1
6
Black Orange Red Yellow

6 1 6 7

Analysis of data
Bush
Actual frequency
Black
Green
Orange
Red
Yellow
Totals
Pop1
5
2
1
9
3
20
Pop2
4
5
4
4
3
20
Pop3
7
1
1
2
9
20
Expected Frequency
16
8
6
15
15
60

5.3
2.6
2
5
5


Green and orange are lower than 3 so colours have to be merged. We decided to merge (green and yellow) and (orange and red) as those colours look similar in a population.

Bush-Merged

Black
Green/Yellow
Orange/red
Totals
Pop1
5
5
10
20
Pop2
4
8
8
20
Pop3
7
10
3
20
Expected Frequency
16
23
21
60

5.3
7.6
7


(O-E) /E=5.025
The P value is higher than the critical value so it is significant. We can accept the null hypothesis. Frequency of polymorphism of snails (Cepaea Nemoralis) will not be high in certain habitats, which suggests gene flow. There will be no selection. Variation will not be down to gene flow and genetic drift. We can also say the difference in the P value is due to sampling error.
Wood
Actual frequency
Black
Green
Orange
Red
Yellow
Totals
Pop1
7
1
2
2
8
20
Pop2
4
6
9
1
0
20
Pop3
6
0
1
6
7
20
Expected Frequency
13
7
12
9
15
60

4.3
2.3
4
3
5


Green is lower than 3 so colours have to be merged. We decided to merge (green and yellow) as those colours look similar in a population.

Wood-Merged

Black
Green/Yellow
Orange
Red
Totals
Pop1
7
9
2
2
20
Pop2
4
6
9
1
20
Pop3
6
7
1
6
20
Expected Frequency
13
22
12
9
60

4.3
7.3
4
3

(O-E) /E=0.0753
The P value is lower than the critical value so it is significant. We can accept the null hypothesis. Frequency of polymorphism of snails (Cepaea Nemoralis) will not be high in certain habitats, which suggests gene flow. There will be no selection. Variation will not be down to gene flow and genetic drift. We can also say the difference in the P value is due to sampling error.